Mass Stays the Same When Ice Melts or Sugar Dissolves

Hey there, I'm Atlas, and I have a question for you: if you put an ice cube on a scale and it reads 50 grams, what will the scale read after the ice melts into water? Here is the secret: the answer is still 50 grams! Let me show you why. All matter — ice, water, sugar, you, everything — is made of incredibly tiny particles called molecules. You cannot see them without a powerful microscope, but they are always there. When ice melts, those water molecules do not disappear. They were packed tightly together as a solid, and now they are moving around more freely, no longer locked tightly in place as a liquid. Every single molecule is still there. That is why the mass stays the same. Now think about sugar dissolving in water. When you stir sugar into a glass of water, the sugar seems to vanish — but it did not go anywhere! The tiny sugar molecules spread out evenly through the water molecules. If you weighed the glass of water before adding the sugar and then weighed the water-plus-sugar together, the total mass would be exactly the same. The particles are just mixed together now. Here is the big idea to remember: a physical change like melting or dissolving moves particles around, but it never creates or destroys them. No matter hiding, no matter lost — the total mass always stays the same.